Spark plug



Jan. 28, '1930. H. T. zuLAwNsK 3 35 SPARKVPLUG Filed May 2, 1928 Patented Jan. 28, 1930 UNITED STATES HAROLD T. ZULAWINSKI, OF PORTLAND, OREGON SPARK PLUG Application filed May 2, 1928. Serial No. 274393.

This invention relates generally to internal combustion engines, and particularly to spark plugs such as are commonly used in connection therewith. i

The main object of this invention is to construct a spark plug which will be self-cleaning and which will not become short circuited due to fouling.

The second object is to construct a plug having an intense spark which occurs within a recess formed in the porcelain shell of the The third object is to design a plug which will be easy to construct and not liable to get out of order on account of delicate or fragile parts.

The fourth object is to so construct the plug that any oil reaching the central electrode will run to its pointed end where it will be burned off or drip therefrom, and any oil which reaches the ground electrode will run to that portion of the electrode subjected to the heat of the combustion and to the rapidly passing gases, which will sepa rate it from the electrode, and in any event it can never collect on that portion of the ground electrodes where the sparking occurs. The fifth object is to so construct the end of the spark plug body that it will afford the minimum amount of lodgment for carbon, and that any carbon which is deposited on same can be easily removed therefrom on account of the shape of the plug end.

These, and other objects, will become more apparent from the specification following as illustrated in the accompanying drawing, in which: i

Figure l is a sideelevation of the plug showing same mounted on the cylinder head which is shown in section. F igure 2 is a vertical section through the plug. Figure 3 is a bottom view of the plug. Figure 4 is a perspective view of the bottom or firing end of the plug. Figure 5 is a fragmentary section taken along the line 5-5 in Figure 3.

Similar numbers of reference refer to similar parts throughout the several views.

Referring in detail to the drawing, the plug itself consists of a body 10 whose end 11 is threaded and whose opposite end 12 is hex- `21 and its pointed end 2'Z reaches approXii within the hexagonal portion 12, and the outermost portion of the counterbore is threaded to receive the nut 20. lVithin the body 10 is placed a porcelain core or shell 21 provded with a central flange 22, on each side of which is placed a gasket 23, which gaskets are held firmly in position by the nut 20.

One end 24 of the core 21 extends to the bottom line 19 of the body 10 and is provided with a hemispherical recess 25. A central electrode 26 passes aXi-ally through the core mately to the line 19 and lies between the ends 5 18 of the ground electrodes 17. The opposite end of the core 21 has mounted thereon a metal cap 28 through which projects the electrode 26 whose outer end 29 is threaded to receive the clamping nuts 30 for the igni tion wires.

In operation the plug is used in the same manner as is the usual type of spark plug but, due to the fact that the sparking occurs within the recess 25, this portion of the plug 35 is always free from carbon, and, owing to its shape, is always accessible for cleansing purposes without the necessity of taking the plug apart with the attendant possibility of changing the adjustment thereof. 99

It is a well known fact that many types of spark plugs have been constructed in the past; it is therefore not my intention to cover such devices broadly, but I do intend to cover all such forms and modications there of as 'fall fairly within the appended claim.

I claim:

A spark plug 'the combination of a body having one of its ends threaded for mounting in a cylincler head, the extreme end of said plug which enters said cylinde' head having a chamfe'ed face, a porcelain core mounted in said body extending to the tip of said chamfei'ed face, the end of said core nearest said chamfered face having a recess fo'nied the'ein, an eleetrode mounted in said core having a pointed end projecting into said 'ecess, and a pair of U-shaped ground electrodes one side of each of which is mounted in said body and the other side projecting into said i'ecess, the middle poi'tions of said g'ound electrodes cu'ving beyond the OUtCl' limits of the plug, the spark gap fol-med by said electrodes lying relatively within said recess.

HAROLD T. ZULAXVINSKI. 

